地表热红外辐射的小波分析及其在现今构造活动研究中的意义

地表热红外辐射的影响因素较多，不仅受到构造活动的影响，还受到大气、太阳以及植被等多种因素的干扰.如何排除这些因素的干扰，是热红外遥感用于研究断层活动或者地震活动的难点之一.从频率域看，地表热红外辐射主要存在3种频段：(1)高频, 周期小于1年的天气变化；(2)中频,以1年周期为主的太阳、植被与季节变化； (3)低频，大于1年周期的大气变化的长周期成份，地壳缓慢的运动引起的热辐射变化亦属于长周期变化.本文运用小波理论将地表热红外辐射分解为上述3个频率成份，并结合气象资料和地震活动进行综合分析.结果表明，低频成份的热异常更接近于断层活动所引起的热信息，能为断层或地震活动提供一定的指示信息.低频成份的高温异常区(条带)跟构造特征、地震活动密切相关.

Wavelet analysis of thermal infrared radiation of land surface and its implication in the study of current tectonic activities

Thermal infrared radiation of land surface(TIRLS) is influenced by many factors such as tectonic activity,atmosphere,solar radiation,plant and so on.How to exclude the non-tectonic information is a key problem before TIRLS is applied to study tectonic activity or earthquake activity.As for frequency domain,TIRLS includes mainly 3 frequency bands:(1)high frequency band with period less than 1 year,which is relative to weather;(2)mid frequency band with predominant period 1 year,relative to sun,plant and season;(3)low frequency band with period more than 1 year,relative to the crustal activity and long period variation of atmosphere temperature.In this paper,TIRLS is decomposed into 3 exclusive frequency bands mentioned above by wavelet method.Compared with weather data and earthquake activity,our result shows that thermal abnormality of low frequency part of TIRLS is resulted most possibly from fault activity and could offer a certain indictor for judging current tectonic activity or earthquake.The high temperature abnormality area(or belt) of low frequency part of TIRLS is likely to attributed to the current tectonic activity and earthquake.